1. Field of the Invention
The present invention relates to a new and novel hinged or door-type rotary nozzle adapted to be attached to the bottom pouring nozzle of a ladle which contains molten metal, or to a converter for transporting or pouring purposes to permit the outflow of the molten metal. More particularly, the invention relates to a hinged or door-type rotary nozzle of the type in which a rotor is mounted for rotation on the outer periphery of a fixed plate supporting frame through a bearing, and in which a sliding plate supporting frame is secured to the rotor by means of a hinge such that the sliding plate supporting frame may be opened and closed like a hinged door, as occasion demands, to thereby eliminate any preliminary setting for changing and maintenance of the bricks, and to make the changing and maintenance easier, and in which a plurality of spring cases each housing a spring for pressing a sliding plate brick against a fixed plate brick are provided therein, either with spring guide means or with stopper means to thereby prevent the leakage of molten metal.
2. Description of the Related Art
It is well known in the art that a rotary nozzle can be attached to the pouring nozzle of a ladle that contains molten metal for transporting and pouring purposes, or attached to the pouring hole of a converter to permit the pouring operation to be conducted more safely and accurately. Known rotary nozzles have been increasingly used along with the recent remarkable technical progress in such areas as the development of large sized ladles, continuous casting, etc. However, although many substantial advantages of the use of known rotary nozzles have been recognized, the actual circumstances have been such that the installation of a rotary nozzle on a ladle, a converter, or the like, requires that the rotary nozzle be preliminarily set at one location, transported to the location of a ladle, and then changed for the old one, which in turn will be transported to a location where the removed rotary nozzle is set again. As a result, it has been the practice to carry out the brick changing and so on in the course of the preliminary setting, and thus it has been impossible to minutely inspect, for example, the extent of wear of the bricks without disassembling the nozzle. Moreover, such preliminary setting requires a good deal of space and the changing operation requires not only extensive equipment, but also much time, including the setting time, thus producing a detrimental effect on costs.
The door-type rotary nozzle, which has enabled the rotary part inclusive of the sliding plate brick to be opened and closed through attachment by a hinge, has come into widespread use because of a number of advantages proper thereto such that the sliding surface can be exposed for inspection by the naked eye of the state of the plate surface of the stationary bottom plate brick or the sliding plate brick once the valve is opened, and that there is no need to have spare sets in store when the brick is exchanged or repaired, thus facilitating the exchange operation.
Further, known rotary nozzles include springs for pressing a sliding plate brick against a fixed plate brick, and because the springs are each mounted between the bottom plate of a spring case attached to the ladle base plate, or the like, to depend therefrom, and the lower surface of the sliding plate supporting frame, if, due to sliding movement and other causes during the pouring operation, molten metal penetrates from the bore edge portions, a phenomenon which is usually called "metal penetration" occurs around the nozzle bores of the fixed plate brick and the sliding plate brick, and in extreme cases the plate bricks will be borne by the penetrated metal. Simultaneously, due to the fact that the resiliency of the springs provided to press the fixed and sliding plates bricks closely against each other acts until the lower limit of their resiliency or the bottom dead center is reached, a gap will be produced between the bricks with resulting leakage of the molten metal through the gap.